The former Bosnian Serb leader Radovan Karadzic is on trial at the International Criminal Tribunal for the former Yugoslavia (ICTY) at The Hague. He is accused of genocide and war crimes committed during the 1992-95 Bosnian war. He has denied the charges.

Here is a breakdown of key events at the trial so far:

Prosecution witnesses

17 August 2010:

As the trial resumes after a summer break, the former United Nations senior military observer for Sarajevo, Richard Mole, describes the siege of Sarajevo.

Mr Mole says the intensity of the shelling by Bosnian Serb forces was "unbelievable", and that the UN ran out of space to record the attacks on its forms.

The prosecution introduces the first of as many as 410 witnesses it may call. Bosniak Ahmet Zulic tells how his elderly father-in-law was burned alive by Serb forces "mopping up" the survivors of an artillery attack.

Mr Karadzic asks Mr Zulic several questions about his political allegiance.

Postponement appeal rejected

1 April 2010:

The court says the trial will resume on 13 April, rejecting Mr Karadzic's appeal to have it postponed until June to give him more time to prepare. Presiding Judge O-Gon Kwon had adjourned the trial on 2 March so the appeal could be considered.

Karadzic's opening statement

1 March 2010:

Mr Karadzic appears for the first time in a non-procedural hearing. He insists he is ready to participate - indeed preparing with "great enthusiasm" - but still stretched for time.

He spends two days outlining his case - that Bosnia's Serbs were acting in self-defence against a Muslim elite who wanted total power in Bosnia.

"I will defend that nation of ours and their cause that is just and holy," he says.

He dismisses some of the most infamous features of the Bosnian war - the massacre at Srebrenica, the siege of Sarajevo, the detention camps - as "myths", designed to arouse Western sympathy for the Bosnian cause.

Signalling his intention to prevent the court proving he was responsibility for any atrocities, he states: "It is going to be easy from me to prove that I had nothing to do with it."

Prosecution outlines case

27 October 2009:

Even though Mr Karadzic continues to boycott his trial, the judges rule that proceedings will continue without him.

Judge Kwon says the defendant had chosen not to exercise his right to be present and "must therefore accept the consequences", adding that the court would consider imposing a lawyer to represent Mr Karadzic if he continues to boycott proceedings.

Outlining its case, the prosecution brands Mr Karadzic the "undisputed leader" of Serbs responsible for carrying out an ethnic cleansing campaign during the 1992-1995 conflict, in which he had "harnessed the forces of nationalism, hatred and fear" to pursue his vision of a state without Muslims.

Mr Karadzic had "ethnically cleansed vast portions of Bosnia and Hercegovina" during the war, says Alain Tieger for the prosecution.

He quotes Mr Karadzic as saying before the war that Serb forces would turn the Bosnian capital, Sarajevo, into "a black cauldron, where 300,000 Muslims will die".

Trial opens

26 October 2009:

The trial opens but Judge O-Gon Kwon adjourns it almost immediately as Mr Karadzic, who is representing himself, refuses to appear.

He says he still needs at least nine months to prepare his defence due to the scope of the case - which is thought to involve 1.2 million pages of evidence, numerous crime scenes and hundreds of witnesses.

Although Mr Karadzic had refused to enter pleas, he had previously said he would co-operate with the court to prove his innocence.

His legal counsel in Belgrade says Mr Karadzic will not attend the second day's proceedings unless the lengthy delay is granted, adding that he would also reject any counsel imposed by the court.